package com.sso.server.util;

import com.sso.core.conf.SSOConf;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * img.Tools
 */
public class ImgUtil {

    public static String genKaptcha(HttpServletResponse response, HttpServletRequest request) {
        response.setContentType("image/jpeg");
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);


        int width = 60, height = 20;
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        Random random = new Random();
        // 设定背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        // 设定字体
        g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
        // 随机产生干扰线
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 155; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }
        String source[] = new String[] { "A", "B", "C", "D", "E", "F", "G", "H", "J", "K", "L", "M", "N", "P", "Q", "R", "S", "T", "U",
                "V", "W", "X", "Y", "Z", "2", "3", "4", "5", "6", "7", "8", "9" };
        String sRand = "";
        for (int i = 0; i < 4; i++) {
            String rand = source[random.nextInt(source.length-1)];
            sRand += rand;
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            g.drawString(rand, 13 * i + 6, 16);
        }

        g.dispose();

        request.getSession().setAttribute(SSOConf.KAPTCHA_CODE, sRand);
        request.getSession().setMaxInactiveInterval(SSOConf.KAPTCHA_CODE_TIME_SECOND);
        try {
            ImageIO.write(image,"jpg",response.getOutputStream());
        } catch (Exception e) {
            e.printStackTrace();
        }

        return sRand;
    }

    private static Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }
}
